As you know, 'When I Look At You' was originally featured on Miley's 'The Time of Our Lives' EP, but when the Last Song team heard it, they felt it was ideal for the film as well.
"'When I Look At You' was a song that really just describes this entire movie," Miley says in the video interview. "We ended up listening to it and were like, 'Oh my gosh this could not go more perfectly. This is such a soundtrack song.'"
Miley learned the instrument in order to add a realness to the movie, which is about a piano prodigy named Ronnie. "We listened to it and we had a composer come in and make a piano piece for me to be able to play, which is when I reveal to Will that I play the piano -- that I have that secret."
Even though Miley won't be making records anymore, she says that she'll continue playing piano. "I'm definitely going to stick with piano," she adds. "I picked up on it really fast -- I guess from playing guitar and from just loving music -- and the way that I learned is I would sing it and then just kind of play along."
It seems she's a natural. Check out the full featurette below, and watch Miley and her co-star/boyfriend Liam Hemsworth acting super flirty while asking each other questions in their Unscripted interview. The Last Song is now playing in theaters nationwide.